Time-Sensitive Award Mechanism ? Using Exposure Science to Identify Populations at Risk in the Aftermath of Hurricane Harvey Summary Hurricane Harvey made landfall on August 26th in Rockport, Texas. Unprecedented rain from the storm dumped over 50 inches on the Houston region. Ten counties were declared disaster areas due to the storm. Preliminary satellite imagery analysis indicates that 730+ square kilometers of land were flooded in Harris and Galveston counties, with a significant portion residential. The greater Houston area includes roughly 570 chemical plants, 43 Superfund sites (13 of which flooded), 9 refineries, 188 cement batch plants, 80 metal recycling facilities, as well as numerous underground storage tanks. Receding flood waters will likely result in widespread mold and potentially bacterial contamination in residential and commercial structures. The extent of toxic contamination of the air, water, and soil has yet to be assessed. There is also uncertainty related to the complex mixtures of contaminants, as well as the impact of psychological stress. The potential for health risk is clear. The scope and scale of the storm event calls for an innovative approach to understanding the environmental health risks in the aftermath of Hurricane/Tropical Storm Harvey. We propose to use state of the art data and exposure science to identify WHO was (and continues to be) exposed to WHAT and in so doing establish baseline understanding of the risks for longer term environmental health effects from the storm. Our specific aims are to: 1) develop an open web platform for storing, sharing, and analyzing data from the greater Houston area; 2) enroll individuals who did and did not experience flooding into a pilot registry and collect basic health and housing information on them; 3) integrate all available environmental exposure data related to the storm into the project's spatial data architecture; 4) identify vulnerable individuals and populations based on their exposures and characteristics; and 5) make the resources developed under this R21 available to the larger research and public health communities. The proposed work leverages a rich array of resources available through Rice and through our strong partnership with the City of Houston and the Environmental Defense Fund. We maintain the Houston Urban Data Platform, which is a secure data repository that holds over 5Tb of geo-referenced curated data related to the greater Houston area. Team members have a long history of collaborating toward a deeper understanding and improved real-time management of environmental exposures for residents of the greater Houston area. Team members also bring extensive experience in community-engaged activities, post-hurricane research, and research dependent on participant recruitment.